What gives henna its dying/coloring specialty?

Henna plant contains Lawsone (Molecular formula: C₁₀H₆O₃; IUPAC Name:2-Hydroxy-1,4-naphthoquinone), the essential dye responsible for the natural coloring of Henna plants.

Powdered Henna leaves contain between 1% and 2% of Lawsone, the essential pigment giving Henna its coloring/dying properties. However, the most desired concentration is the one closest to 2%. Henna products that fail to maintain a high concentration of Lawsone tend to add chemical substances to the powder such as PPD in order to strengthen the dye.